(a) Field
Embodiments of the present invention relate generally to flat panel displays. More specifically, embodiments of the present invention relate to curved display devices with resistance to excessive bending.
(b) Description of the Related Art
Common display devices include liquid crystal displays (LCDs) and organic light emitting displays (OLEDs).
The LCD displays images by applying voltages to field-generating electrodes to generate an electric field in the LC layer. This electric field determines the orientations of LC molecules of the LC layer, to adjust polarization of incident light. Differently from the liquid crystal display, the OLED has a self-luminous characteristic, does not require a separate light source, and displays an image through a display substrate in which a thin film transistor and an organic light emitting element are formed.
Recent efforts have focused on increasing the screen size of both LCDs and OLEDs. However, when the size of these display devices is enlarged, the center portion of the screen begins to appear different from the left and right ends of the screen.
To compensate for such difference in the visual field, it is possible to form a display device in a curved shape by bending the display device to have a concave shape or a convex shape. The display device may be provided as a portrait type format having a longer vertical length than a horizontal length and bent in a vertical direction, or may be provided as a landscape type format having a shorter vertical length than a horizontal length and bent in a horizontal direction.
However, when a display device is bent, a compressive stress is applied to one side of the curved surface and a tensile stress is applied to the other side of the substrate. In the case of bending the display device to more than a predetermined curvature, cracks may be generated in the substrate and damage to the panel may result.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.